That counts for the MEL engine family. It was a unique engine with no smaller sibling. As for other FORD engines the 351 or 302 for instance are small bocks while 390, 427, 428, 462 are considered big blocks

ther is always the discussion if a MEL is a Biugblock or small Block. Ford did not answer this question in discriptions.
Is ther a short answer?

The MEL has 2" in length, wider and taller than the big block FE. Today I dollied a 352, minus rods and pistons, including the crank and main caps. I also dollied a 1960 MEL without a crank or main caps. They felt about the same weight. Compared to there Super Duty series cousin the MEL could be a small block.

The small block / big block distinction gets a bit annoying when talking about anything other than Chebbies. The being said, a little food for thought.

The 2 most commonly referenced dimensions when talking about block size are bore spacing and deck height.
The MEL has a 4.9" bore spacing and 10.482" block height.

The MEL bore spacing was only exceeded by the 5.0" bore spacing in Packard V8's (max 374 ci) and Cadillac V8's (max 500 ci), and the rather comically large 5.25" bore spacing of Ford's Super Duty V8's.

The MEL deck height by comparison is rather short when compared to Lincoln Y-Blocks (max 368 ci) at 10.94", Chrysler 392 at 10.87", or even the 455 Oldsmobile at 10.625", but still larger than the 385 series Fords (429/460) at 10.3"

In the end, To me it is an MEL block, or an FE block, or a Lincoln Y-block. Let the Chebbie guys fight over big and small blocks. No doubt the MEL is on the larger end of the spectrum when comparing other American V8's, but still smaller then engines with significantly smaller displacements (Lincoln Y and Packard)

Short answer is all M-E-L engines are considered big blocks. It's generally accepted that engines with less than 4.500" between bore centers are small blocks and engines greater than this are big blocks. Ted Eaton.

Ted Eaton --- http://www.eatonbalancing.com/ --
Big Engines are quick but it's hard to beat the fun that comes from running a normally aspirated Y-Block at 8.80's and 147 mph in the quarter.